1. Field of the Invention
This invention relates to an operating device which is operated by depressing an operating element.
2. Related Art
Unexamined Japanese Patent Application Hei 7-2388063 has disclosed a switch device in which an operating protrusion is formed on its operating shaft side, and a rotary protrusion is formed on its rotary element side. The operating protrusion, and the rotary protrusion have linearly sloped surfaces which are abutted against each other. When the operating knob is depressed against the elastic force of a return spring interposed between the operating knob and a switch body, the operating protrusion and the rotary protrusion are abutted against each other, so that the rotary protrusion is turned. As the rotary protrusion is turned, the switch member is operated.
In the switch device, when the operating shaft is depressed, the elastic force (or operating force) of the return spring acting in response to the depression is scarcely changed. Therefore, the feeling of depression of the operating shaft is not dependent on the degree of depression: that is, the switch device is low in operability.
On the other hand, Examined Japanese Utility Model Publication Sho 53-2281 has disclosed a switch in which a shaft is pushed to turn a rotor, to perform a switching operation.
In the conventional switch, the shaft has a gear ring, which is engaged with a gear ring formed on the rotor side. The gear rings on the shaft side and on the rotor side have teeth of the same tangent (tan) curve, and are meshed with each other. The switch is provided with a spring which urges the shaft's gear ring and the rotor's gear ring to space them away from each other. That is, the switch is so designed that, when the shaft is pushed, the shaft's gear ring is engaged with the rotor's gear ring, to turn the rotor. When the shaft is pushed, the distribution of force is as follows; that is, first the force is small, then large, and finally small again. Thus is, the feeling of operation is dependent on the degree of depression. Hence, the degree of depression can be determined from the change in the feeling of operation. Thus, the switch is high in operability.
However, the shaft's gear ring, and the rotor's gear ring must have tangent curved teeth. However, the manufacture of those gear rings takes time and labor. Furthermore, since it is necessary to engag the teeth of the tangent curved gears, the assembling work takes time and labor.
In view of the foregoing, an object of the invention is to eliminate the above-described difficulties accompanying a conventional switch device. More specifically, an object of the invention is to provide an operating device which is simple in structure, and in which the feeling of operation is improved.